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Step 1 - nginx-proxy

Start nginx-proxy with the three additional volumes declared:

$ docker run --detach \
    --name nginx-proxy \
    --publish 80:80 \
    --publish 443:443 \
    --volume /etc/nginx/certs \
    --volume /etc/nginx/vhost.d \
    --volume /usr/share/nginx/html \
    --volume /var/run/docker.sock:/tmp/docker.sock:ro \
    jwilder/nginx-proxy

Binding the host docker socket (/var/run/docker.sock) inside the container to /tmp/docker.sock is a requirement of nginx-proxy.

Step 2 - letsencrypt-nginx-proxy-companion

Start the letsencrypt-nginx-proxy-companion container, getting the volumes from nginx-proxy with --volumes-from:

$ docker run --detach \
    --name nginx-proxy-letsencrypt \
    --volumes-from nginx-proxy \
    --volume /var/run/docker.sock:/var/run/docker.sock:ro \
    --env "DEFAULT_EMAIL=mail@yourdomain.tld" \
    jrcs/letsencrypt-nginx-proxy-companion

The host docker socket has to be bound inside this container too, this time to /var/run/docker.sock.

Albeit optional, it is recommended to provide a valid default email address through the DEFAULT_EMAIL environment variable, so that Let's Encrypt can warn you about expiring certificates and allow you to recover your account.

Step 3 - proxyed container(s)

Once both nginx-proxy and letsencrypt-nginx-proxy-companion containers are up and running, start any container you want proxyed with environment variables VIRTUAL_HOST and LETSENCRYPT_HOST both set to the domain(s) your proxyed container is going to use.

VIRTUAL_HOST control proxying by nginx-proxy and LETSENCRYPT_HOST control certificate creation and SSL enabling by letsencrypt-nginx-proxy-companion.

Certificates will only be issued for containers that have both VIRTUAL_HOST and LETSENCRYPT_HOST variables set to domain(s) that correctly resolve to the host, provided the host is publicly reachable.

$ docker run --detach \
    --name your-proxyed-app \
    --env "VIRTUAL_HOST=subdomain.yourdomain.tld" \
    --env "LETSENCRYPT_HOST=subdomain.yourdomain.tld" \
    nginx

The containers being proxied must expose the port to be proxied, either by using the EXPOSE directive in their Dockerfile or by using the --expose flag to docker run or docker create.

If the proxyed container listen on and expose another port than the default 80, you can force nginx-proxy to use this port with the VIRTUAL_PORT environment variable.

Example using Grafana (expose and listen on port 3000):

$ docker run --detach \
    --name grafana \
    --env "VIRTUAL_HOST=othersubdomain.yourdomain.tld" \
    --env "VIRTUAL_PORT=3000" \
    --env "LETSENCRYPT_HOST=othersubdomain.yourdomain.tld" \
    --env "LETSENCRYPT_EMAIL=mail@yourdomain.tld" \
    grafana/grafana

Repeat Step 3 for any other container you want to proxy.